Molding composition



45 quantity of an Patented sem s-193s MOLDING comosmoii Edward Henry George Sargent, Hull, England, as-

, signor t Beckltt & Sons-Limited, Hull land, a corporation of England No Drawing; Application June 5,

No. 83,732. In-GreatBritain June 1936, Serial .2 Claims. (Cl. 280-) The present invention relates to the production of synthetic resin molding compositions which are capable of being converted into powder for use as molding powders. More particularly the invention is concerned with compositions ob tained from crude tar acids and especially from ordinary commercial cresylic acid and formaldehyde. By ordinary commercial cresylic acid I mean any grade of cresylic acid obtainable by 'simpledistillation' of coal tar without reference to the relative percentages of theisomers-ortho, meta and para cresols-contained therein.

The process of obtaining a molding composition by condensing together cresylic acid and 1 formaldehyde using definite proportions of caustic alkali as a condensing agent is well known and has been the subject of tions, using ordinary commercial cr'esylic acid none of these processes produces a commercially acceptable. pr'oduct, although I am aware that if speclally selected cresylic acids, containing little or no ortho-cresol are used; acceptable molding powders can be'produced. Therehave also been many proposals for the use of proteins in plastic masses but the-object of all the latter proposals has been the production of hard substances which are infusible and which cannot thermosetting molding powders.

'30 The object .0! the present process is the production of a composition for'convertlng into a molding powder'whichcan be very rapidly prepared from cheap-materials, which isv moldable b'yheat and pressure without the further additions oj.

hardening agents such as 'lime, hexamine or paramore rapidly and at a lowerformaldehyde, and temperature than those compositions hitherto proposed, and which does not contain free phenolic bodies and so does not readily discolour and 40 is exceptionally chemically inert.

According to the present tar acids, preferably ordinary commercial cresylic acid and formaldehyde, with the use of a small alkaline or acid-dispersion of a protein as the condensing agent. The preferred proteinemployed is that obtained from rice, but proteins obtained from soya bean, wheat, maize, milk, glue or other materials may be used. The

yield of resinous compositions'from such cresylic acid and formaldehyde mixtures is definitely increased by the addition of protein amounting to as little as 5% of the crcsylic acid. .An excess of protein over that which can be eflectively dis-i many patent specifica-' but it has been found by experiment that 1 be converted into.

-ment may be ground.

invention a molding composition is produced by condensing together persed by the alkali may be present in the composition it desired up to 50% of the cresylic acid used. The protein is conveniently dispersed by using say five times its volume of water and the requisite alkali or acid and heating it for say half an hour at around 95-98 C. in any case hydrolysis of the protein should be incomplete. As an example of us out the p following illustration is given:-

Five to fifty parts by weight of a protein are dispersedor partially dispersed according to the amount of protein taken, in a suitable volume'of the water by not more than two parts by weight of mended alkalies in the above process.

The acid may be mineral acid-or a substance producing a mineral acid solution when added to as too, acetic,

oxalic acid or a halogen substituted acid such as chlor-acetic acid.

The whole is now well stirred and the mixture condensed at a temperature about 95-100" C; for a suitable time, usually a ut one hour. The resulting product is washed free of the residual reactive liquor by treatment with concentrated "hydro-chloric acid and then dried at a low tem- The product without further treatmixed with dyes and fillers and used as a molding powder.

What I .claim"is:--I 1. A process for: preparing a molding composition which consists in dispersing 5 to' 50 parts by perature.

parts of alkali,adding, the dispersion-to 100 parts of cresylic acid and to 100 parts of a 35- 40% aqueous solution of formaldehyde, condensing by any other suitable-allrali, and the weight of a protein in water by not more than2 stirring and heating the mixture to about' 4 to washing the condensed product with concentrated hydrochloric acid, and drying the product at low temperature.

2. A process according to claim 1 in which the product is ground and mixed with dyes and fillers.

j nnwaan HENRY GEORGE smonn'r. 

